Touch systems are well known in the art and typically include a touch screen having a touch surface on which contacts are made using a pointer in order to generate user input. Pointer contacts with the touch surface are detected and are used to generate corresponding output depending on areas of the touch surface where the contacts are made. Common touch systems utilize analog resistive, electromagnetic, capacitive, acoustic or machine vision to identify pointer interactions with the touch surface.
For example, International PCT Application No. PCT/CA01/00980 filed on Jul. 5, 2001 and published under No. WO 02/03316 on Jan. 10, 2002, assigned to SMART Technologies Inc., assignee of the present invention, discloses a camera-based touch system comprising a touch screen that includes a passive touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports digital cameras at its corners. The digital cameras have overlapping fields of view that encompass and look across the touch surface. The digital cameras acquire images from different locations and generate image data. Image data acquired by the digital cameras is processed by digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x,y)-coordinates relative to the touch surface using triangulation. The pointer coordinate data is conveyed to a computer executing one or more applications programs. The computer uses the pointer coordinate data to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or drawing or used to control execution of applications programs executed by the computer.
Although the above touch system works extremely well, since the field of view of each camera is arranged to encompass the entire touch surface, camera resolution has placed a limit on the size of the touch system that can be made.
In many environments such as in teaching institutions, large scale touch systems are desired so that visible presentations can be made to large groups. A large scale touch system created from a series of side-by-side mounted touch panels has been considered. Although this touch system provides a larger touch surface, the touch surface is not continuous due to the individual frames surrounding the touch surfaces. Also, tracking pointer movements from one touch surface to another is cumbersome and user unfriendly.
A large scale touch system that overcomes the above-noted problems is disclosed in U.S. patent application Ser. No. 10/750,219 to Hill et al. and assigned to SMART Technologies Inc., assignee of the present invention. This large scale touch system includes a touch surface divided into a plurality of coordinate input sub-regions. The input sub-regions overlap to define a generally contiguous input surface. Each coordinate input sub-region generates pointer coordinate data in response to pointer contacts thereon. The pointer coordinate data is processed to update image data presented on the input surface. When a pointer contact is made on a coordinate input sub-region that does not overlap with an adjacent coordinate input sub-region, the coordinate input sub-region processes acquired images to derive pointer data and triangulates the position of the pointer using the derived pointer data thereby to determine the position of the pointer contact relative to the touch surface. When a pointer contact is made on a coordinate input sub-region that overlaps with an adjacent coordinate input sub-region, each overlapping coordinate input sub-regions processes acquired images to derive pointer data and triangulates the position of the pointer using the derived pointer data. Thereafter, the triangulated positions generated by the overlapping coordinate input sub-regions are processed in accordance with defined logic thereby to determine the position of the pointer contact relative to the touch surface.
The above-noted Hill et al. large scale touch system provides a contiguous touch surface making it extremely useful in environments where the touch surface is to be viewed by larger groups. Increasing the size of the touch surface however presents challenges. Various situations can arise where a user cannot readily physically interact with the touch surface. For example, depending on the size of the touch surface and the physical size and/or condition of the user, the user may not be able to reach upper regions of the touch surface. Also, situations may arise where the user is standing to one side of the touch surface but needs to interact with image content displayed adjacent the opposite side of the touch surface. Having to walk to the opposite side of the touch surface to interact with the touch surface is inconvenient and may result in the image presented on the touch surface being disrupted or obscured. Furthermore, the size of the touch surface can make it difficult for a user to identify visually displayed objects such as modal boxes. As will be appreciated, methods of interacting with such large scale touch systems to facilitate user interaction are desired.
It is therefore an object of the present invention to provide a novel large scale touch system and methods of interacting with the same.